Replace public library list with shared lib sonames (part 1/2)

Replace public library list with shared lib sonames
which are property of a link between namespaces

This change does not touch any external interfaces
so from outside it behaves almost as it was before

One significant difference is that there is no longer
need to preload public libraries.

Bug: http://b/26833548
Test: bionic-unit-tests --gtest_filter=dl*:Dl*
Change-Id: I57e44e18a9b4f07dcd6556436346be52f52b79d7